Large weatherproof electrical enclosures typically house multiple control modules, power distribution components, terminals, power supplies, or systems requiring ample maintenance space. Sizing cannot rely solely on component dimensions; it must also account for cable bend radiuses, subpanel reinforcement, terminal clearance, door cutouts, and future expansion space.

For the internal layout, organize by power, control, communication, terminal, and maintenance zones. Heavy equipment should be mounted on adequately reinforced structures, heat-generating components kept clear of temperature-sensitive devices, and entry areas aligned with incoming cables to minimize long cross-routing.

Large enclosures also demand attention to shipping, lifting, foundations, and shifts in center of gravity when doors open. Verify anchor points, brackets, lifting lugs, and door clearance before installation to prevent on-site fitting or access issues.